# HydroCalc Basic vs Culvert Studio

The clearest difference is in-app purchases: Culvert Studio at none against HydroCalc Basic's 1. Culvert Studio also leads on update cadence (daily vs every 11 days). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. HydroCalc Basic sells 1 one-off in-app purchase. Culvert Studio asks for nothing beyond the download.

HydroCalc Basic ships an update every 11 days, Culvert Studio daily. The most recent releases landed on October 4, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | HydroCalc Basic | Culvert Studio |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 11 days | **Daily** |
| Size | 35 MB | 43 MB |
| Requires iOS | **15.1** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Transparent Blue Water LLC](https://appshunter.io/developer/1847968351) | [Jagdeep Singh](https://appshunter.io/developer/1865361721) |

## What reviewers say

### HydroCalc Basic

[App page](https://appshunter.io/ios/app/hydrocalc-basic/id6752577110)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium - Flow Units & Ad-Free | $1.99 | one-time |


### Culvert Studio

[App page](https://appshunter.io/ios/app/culvert-studio/id6758688358)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is HydroCalc Basic free?

HydroCalc Basic is free to download, with in-app purchases available.

### Is Culvert Studio free?

Culvert Studio is free to download, with no in-app purchases.

### Do HydroCalc Basic or Culvert Studio have ads?

Neither HydroCalc Basic nor Culvert Studio shows ads.

### Which is updated more often, HydroCalc Basic or Culvert Studio?

HydroCalc Basic ships an update every 11 days, and Culvert Studio daily. Most recently, HydroCalc Basic was updated on October 4, 2026 and Culvert Studio on October 2, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*